Geochemical variables and fluoride ion concentration levels impart infectious diseases: A systematic study of fluoride ion removal using natural adsorbents at low cost

2020 ◽  
Vol 11 (1) ◽  
pp. 256
Author(s):  
B Joseph
2021 ◽  
Vol 42 (1) ◽  
pp. 89-98
Author(s):  
Mandira Pradhananga Adhikari ◽  
Sandeep Sharma Lamsal

Phosphoric acid-activated Terminalia-bellerica (Barro) seed stone powder was carbonized in a muffle furnace at three different temperatures (300, 400, and 500oC). The activated carbons (BAC-300, BAC-400, and BAC-500) were characterized by using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), methylene blue number, and iodine number. The iodine number (357 mg/g) and specific surface area (537 m2/g) were a maximum for BAC-400. The BACs followed Langmuir adsorption isotherm and the maximum methylene blue adsorption capacity was 212.77 mg/g. The silver ion removal efficiency was a maximum at pH 6, 3 mg/L of adsorbent dose, and 20 mg/L of silver ion concentration. The BAC-400 could adsorb 40 % of silver ion within 5 mins with the initial Ag(I) ion concentration of 20 mg/L and an adsorbent dose of 1 mg/L. The percentage of adsorption enhanced to 100% with the increment of adsorbent doseto3 g/L.The adsorption kinetics of silver (I) ion on BAC-400 was well fitted to pseudo-second-order kinetics suggesting the chemisorption of silver ions. All the results attributed that low-cost viable adsorbent can be prepared from Barro seed stone for the efficient removal of silver ion from aqueous solution.


Biomolecules ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1072
Author(s):  
Raquel Cid ◽  
Jorge Bolívar

To date, vaccination has become one of the most effective strategies to control and reduce infectious diseases, preventing millions of deaths worldwide. The earliest vaccines were developed as live-attenuated or inactivated pathogens, and, although they still represent the most extended human vaccine types, they also face some issues, such as the potential to revert to a pathogenic form of live-attenuated formulations or the weaker immune response associated with inactivated vaccines. Advances in genetic engineering have enabled improvements in vaccine design and strategies, such as recombinant subunit vaccines, have emerged, expanding the number of diseases that can be prevented. Moreover, antigen display systems such as VLPs or those designed by nanotechnology have improved the efficacy of subunit vaccines. Platforms for the production of recombinant vaccines have also evolved from the first hosts, Escherichia coli and Saccharomyces cerevisiae, to insect or mammalian cells. Traditional bacterial and yeast systems have been improved by engineering and new systems based on plants or insect larvae have emerged as alternative, low-cost platforms. Vaccine development is still time-consuming and costly, and alternative systems that can offer cost-effective and faster processes are demanding to address infectious diseases that still do not have a treatment and to face possible future pandemics.


Author(s):  
David C. Cowell

An automated method is described, using standard continuous flow techniques, for the determination of urine fluoride ion concentration using a fluoride ion selective electrode. It is shown that the kinetics of the electrode response to changes in fluoride ion can be used for the accurate measurement of fluoride ion concentration in urine, and that equilibration of the electrode response is not a prerequisite for the measurement of fluoride ion. Recovery experiments are in the range 83 to 90%; in-batch precision is between 0·9 and 1·6% and carryover 2·5% or less.


2012 ◽  
Vol 65 (8) ◽  
pp. 1435-1440 ◽  
Author(s):  
Thiago L. Marques ◽  
Vanessa N. Alves ◽  
Luciana M. Coelho ◽  
Nívia M. M. Coelho

Metal contaminants are generally removed from effluents by chemical and physical processes which are often associated with disadvantages such as the use of toxic reagents, generation of toxic waste and high costs. Hence, new techniques have been developed, among them the study of natural adsorbents, for instance, the use of Moringa oleifera seeds. The potential of M. oleifera seeds for nickel removal in aqueous systems was investigated. The seeds utilized were obtained from plants grown in Uberlândia/Brazil. After being dried and pulverized, the seeds were treated with 0.1 mol/L NaOH. Fourier transform infrared spectroscopy, scanning electron microscopy and thermogravimetric analyses were used for the characterization of the material. Using the optimized methodology (50 mL of 4.0 mg/L Ni(II), pH range of 4.0–6.0, agitation time of 5 min and adsorption mass of 2.0 g) more than 90% of Ni(II) could be removed from water samples. The sorption data were fitted satisfactorily by the Langmuir adsorption model. Evaluation applying the Langmuir equation gave the monolayer sorption capacity as 29.6 mg/g. The results indicate that this material could be employed in the extraction of nickel, considering its ease of use, low cost and environmental viability, which make it highly attractive for application in developing countries.


2013 ◽  
Vol 125 ◽  
pp. 10-17 ◽  
Author(s):  
S. Gammoudi ◽  
N. Frini-Srasra ◽  
E. Srasra
Keyword(s):  

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Zizheng Yue ◽  
Wenlin Feng

Abstract In this work, a fiber-optic fluoride-ion-detection Michelson interferometer based on the thin-core fiber (TCF) and no-core fiber (NCF) coated with α-Fe2O3/ZrO2 sensing film is proposed and presented. The single-mode fiber (SMF) is spliced with the TCF and NCF in turn, and a waist-enlarged taper is spliced between them. Then, a silver film is plated on the end face of NCF to enhance the reflection. After the absorption of fluoride ion by the sensing film, the effective refractive index (RI) of the coated cladding will change, which leads to the regular red shift of the interference dip with the increasing fluoride-ion concentration. Thus, the fluoride-ion concentrations can be determined according to the corresponding dip wavelength shifts. The results show that the sensor has an excellent linear response (R 2 = 0.995) with good sensitivity (8.970 nm/ppm) when the fluoride-ion concentration is in the range of 0–1.5 ppm. The response time is about 15 s. The sensor has the advantage of good selectivity, good temperature and pH stabilities, and can be applied to detect fluoride ion effectively.


2011 ◽  
Vol 14 (3) ◽  
pp. 400 ◽  
Author(s):  
Ravindra B Malabadi ◽  
Advaita Ganguly ◽  
Jaime A Teixeira da Silva ◽  
Archana Parashar ◽  
Mavanur R Suresh ◽  
...  

ABSTRACT - This review highlights the advantages and current status of plant-derived vaccine development with special reference to the dengue virus. There are numerous problems involved in dengue vaccine development, and there is no vaccine against all four dengue serotypes. Dengue vaccine development using traditional approaches has not been satisfactory in terms of inducing neutralizing antibodies. Recently, these issues were addressed by showing a very good response to inducing neutralizing antibodies by plant-derived dengue vaccine antigens. This indicates the feasibility of using plant-derived vaccine antigens as a low-cost method to combat dengue and other infectious diseases. The application of new methods and strategies such as dendritic cell targeting in cancer therapy, severe acute respiratory syndrome, tuberculosis, human immune deficiency virus, and malaria might play an important role. These new methods are more efficient than traditional protocols. It is expected that in the near future, plant-derived vaccine antigens or antibodies will play an important role in the control of human infectious diseases. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.


2015 ◽  
Vol 9 (13) ◽  
pp. 252 ◽  
Author(s):  
Piyada Wachirawongsakorn ◽  
Tongsai Jamnongkan ◽  
Mohd Talib Latif

<p>Vetiver grass and it usages have been widely investigated in many researches as the preferred plant species due to its known efficiency, low cost, the ease of availability and spread. This research aimed to use four different vetiver grass (<em>Vetiveria zizanioides</em>) ecotypes to remove cyanide (CN<sup>-</sup>)-contaminated water for improve its quality. Growth capability, tolerance and removal efficiency were evaluated. The results showed that the vetiver grass had a 100% survival rate for one month after planting. Songkhlar3 had the longest leaves, followed by Surat-Thani, Sri Lanka and Monto, respectively. Root lengths of all ecotypes showed no significant differences (p ≤ 0.05). All vetiver grass ecotypes could potentially purify CN<sup>-</sup>-contaminated water at lower concentrations of ≤ 35 mg CN<sup>-</sup>/L. The Monto ecotype had the highest CN<sup>-</sup> removal efficiency at all CN<sup>-</sup> concentration levels, showing 100% CN<sup>-</sup> removal from the 5-45 mg CN<sup>-</sup>/L contaminated water samples within 2-5 weeks growth. The tolerance of vetiver grass to CN<sup>-</sup> was a more important factor than growth rate when selecting a vetiver grass ecotype for CN<sup>-</sup> phytoremediation.</p>


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